A new catheterization technique will be used to test the validity of the nonlinear theory of blood flow and pulse propagation in the aorta of a model of the systemic circulation of a dog. Later, similar experiments will be conducted in vivo, in the aorta of dogs. The work on the construction of the highly accurate model of the systemic circulation of dogs will be continued. The work on muscle contraction will be continued to determine the link between the biochemistry of muscle contraction and the electrical polarization stress contraction produces.